SHA1 Generator
What the SHA1 Generator does
Hashing text with SHA-1 condenses any message into a 160-bit digest, traditionally shown as 40 hexadecimal characters. Paste your Text to Hash, press Generate SHA1 Hash, and the fingerprint appears instantly. Legacy databases, old checksum lists, and classic version-control references still carry SHA-1 values, so developers and auditors keep a generator within reach.
You can hash anything from a one-line note to an entire license agreement and always receive the same 40 characters. It remains a perfectly reasonable checksum utility even though its life as a security standard has ended.
How the 160-bit digest is built
SHA-1 pads the input, splits it into 512-bit blocks, and applies 80 rounds of mixing over 32-bit words to emit 160 bits, always 40 hex characters long. Hashing the word hello still gives aaf4c61ddcc5e8a2dabede0f3b482cd9aea9434d, and appending a single period produces an entirely different digest.
The 2017 SHAttered result went further by creating two different PDF files that share one SHA-1 hash, which broke digital certificates and signatures built on it. That collision work is why SHA-1 is officially deprecated for anything an attacker could touch, even though accidental-integrity checking still works.
Running a hash step by step
Type or paste the text into the Text to Hash box, watching for hidden trailing spaces or line endings because every byte counts. Click Generate SHA1 Hash and read the 40-character hexadecimal digest. Compare the result with the checksum provided by a vendor to confirm the file arrived uncorrupted.
For new security-sensitive work, pick SHA-256 or SHA-512 instead, and save SHA-1 for compatibility with older systems. Git migrations are a common example, where repositories of millions of objects still reference 40-character digests.
Frequently Asked Questions
How long is a SHA-1 digest?
SHA-1 always outputs 160 bits, printed as 40 hexadecimal characters. Whether the input is one short word or an entire multi-page book, the digest size never changes.
Is SHA-1 still safe to use?
No, SHA-1 is deprecated for security because researchers demonstrated practical collisions in 2017 with two different PDFs sharing one digest. It remains acceptable for simple checksums where nobody is deliberately forging data.
Why do Git and SHA-1 appear together?
Historically, Git identified every commit and file object by its SHA-1 hash, so older repositories display 40-character digests. Newer Git versions now support SHA-256 object identifiers as well.
Does capitalization affect the SHA-1 hash?
Yes, every character matters, so Hello and hello produce different 160-bit digests. Punctuation, spacing, and line endings all change the result, which is why the exact text must be used.
Can SHA-1 be used for passwords?
Do not hash passwords with SHA-1; it is too fast and collision-broken. Modern practice uses salted, memory-hard schemes like bcrypt or Argon2 that are designed specifically for password storage.